Cannulated injection system

Abstract

A cannulated injection system having or more hollow bodies to receive material to be injected, a piston in each said hollow body to force material from said body through a nozzle having a passageway sized and selected to accommodate flow of the material therethrough and with the passageway arranged to accommodate a guide wire passed therethrough, the guide wire further being passed through support structure including a piston and hollow body in which said piston reciprocates or a support structure for a plurality of hollow bodies in which pistons reciprocates during use in simultaneously injecting material from said hollow bodies through said injection tip and around a guide wire passing through the tip.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] Not Applicable. STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT [0002] Not Applicable. REFERENCE TO MICROFICHE APPENDIX [0003] Not Applicable. BACKGROUND OF THE INVENTION [0004] 1. Field of the Invention [0005] This invention relates to injection systems and more particularly, to a cannulated injection system for orthopedic applications which may be guided to its desired location by a previously placed guide wire. [0006] 2. Description of the Prior Art [0007] Recently a number of healing enhancing products have come to market. These include calcium triphosphates, high hyaluronic acid products, platelet healing factors and others. These materials are used to enhance bone tunnel fixation of soft tissue ligament grafts as well as arthroscopically treating non-unions of long bones, bone cysts of the hip, knee and other related skeletal abnormalities. The sites at which the healing enhancing products must be placed are freque...

AI Technical Summary

Benefits of technology

[0018] Principal features of the invention herein disclosed include a cannulated injection system comprising a cannulated syringe and demountable nozzle, which may be configured for a variety of applications. A cannulated syringe has a clear hollow cylindrical body, including a cannulated distal end with a mounting means to which a nozzle can be mounted and an open proximal end into which a piston assembly is inserted. The piston assembly has a proximal end and a distal end and comprises an outer member and an inner member, with the inner member concentrically and rotatably positioned within the outer member. The inner member may be rotated by a proximal end means so that passages in the inner member and outer member distal ends align to provide an aspiration path through the piston assembly. The piston inner member comprises a cannulation of sufficient size to allow passage of common guide wires of various sizes. A seal made from silicone, or a similar material, within the inner member cannulation, prevents leakage of material through the inner member cannulation during use. A seal prevents leakage through the clearance between the piston assembly and the hollow cylindrical body.

[0020] In an alternate embodiment for use with low-viscosity materials only, the piston assembly does not contain a means for aspirating trapped air therethrough since trapped air can be expelled by pointing the nozzle upward and advancing the piston into the body. The cannulated piston assembly does, however, contain a sealing means for preventing material loss around the guide wire and through the cannulation during use.

[0021] Some injectable, healing enhancing products are supplied as two components which are mixed immediately prior to use, the ratio of the mix being specified by the manufacturer. In another embodiment for use with these low-viscosity, two-component systems, the body of the syringe has to cylindrical barrels, the ratio of their cross-sectional areas being equal to the required mixing ratio of the components. The body of the syringe has a cannulation to allow passage of a guide wire therethrough and a sealing means to prevent material loss through the cannulation during use. The piston assembly has two pistons corresponding in size to the cylindrical barrels, the pistons being connected to a common flange at their proximal ends so that their axial movements are simultaneous.

Problems solved by technology

The sites at which the healing enhancing products must be placed are frequently difficult to access making the required accurate placement of the materials difficult.

The viscosity of the materials to be injected also affects the choice of an injection device and the manner of use of such device.

With currently available devices, removing trapped air is problematic when materials are loaded through the proximal end of the syringe body.

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